The viscosity(η) and surface tension(σ) of ethyl acetate(EA) + isopropanol(IPA) binary mixture were measured over the entire composition range at 298.15—323.15 K and atmospheric pressure using Ubbelohde viscometer and pendant drop method
respectively.Viscosity deviations(Δη)
excess Gibbs energy of activation of viscous flow(ΔG*E) and surface tension deviations(Δσ) were calculated from the experimental data.The excess thermodynamic properties
Δη
ΔG*E and Δσ were correlated by the Redlich-Kister equation
and fitted parameters and standard deviations were obtained.The results show that Δη
ΔG*E and Δσ are negative over the whole mole fraction range in the temperature range studied
and all deviations become larger as temperature decreases.The surface tension values were further used to calculate the surface entropies(Ss) and surface enthalpies(Hs) per unit surface area.The lyophobicity(β) and the surface mole fraction(xs2) of IPA were also derived using the extended Langmuir model.The obtained xs2 values indicate that the surface concentration of IPA is always higher than its bulk concentration and consequently confirm that the surface is enriched with IPA.